Stapling apparatus and method for heart valve replacement

ABSTRACT

There are disclosed various systems and methods for installing a synthetic, artificial heart valve within a patient. One system generally includes a plurality of sutures, each suture having a staple attached to a distal end thereof; a surgical stapler for radially discharging the staples into a heart at a location adjacent a site for installing the heart valve; a support assembly for releasably supporting the plurality of sutures; and a heart valve setter assembly, the heart valve setter assembly being operable to move the heart valve into position within the site in the heart. A method of installing a heart valve within a patient utilizing the system is provided and generally includes the steps of accessing a site within a heart from which a natural heart valve has been removed; positioning a surgical stapler within the site; discharging a plurality or staples, having sutures attached thereto, from the surgical stapler into the heart; lowering the heart valve along the sutures into position within the site in the heart; and securing the heart valve to the heart with the sutures.

This application is a Divisional of prior application Ser. No.09/013,836, filed on Jan. 27, 1998, now U.S. Pat. No. 6,096,074.

BACKGROUND

1. Technical Field

The subject disclosure relates to minimally invasive surgical proceduresand apparatus and, more particularly, to instruments and methods forperforming heart valve replacement surgery.

2. Background of Related Art

The diagnosis and treatment of coronary disease and related conditionsoften requires repair or replacement of the valves located within theheart. Various factors, such as, for example, calcification, may resultin the mitral or aortic valves becoming impaired or functionallyinoperative requiring replacement. Where replacement of a heart valve isrequired, in general, the dysfunctional valve is cut out and replacedwith either an artificial, synthetic heart valve or a harvested porcineheart valve. The replacement valve is typically sutured in place of theoriginal valve.

Access to the heart in a patient's thoracic cavity is achieved by makinga longitudinal incision in the chest. This procedure, referred to as amedian sternotomy, includes cutting through the sternum and forcing thetwo opposing halves of the rib cage to be spread apart allowing accessto the thoracic cavity and thus the heart.

Suitable instruments for spreading and holding apart the rib cage aremarketed by United States Surgical Corporation, Norwalk, Conn. Theseinstruments include, for example, Mini-CABG* retractors and relatedaccessories. The Mini-CABG* universal retractor includes a substantiallyplanar base having an opening which can be positioned on the patientsuch that the opening overlies the incision at the operative site.Mini-CABG* retractors are slidably mounted on the base and are providedto spread apart the rib cage halves and engage and retract obstructingtissue. The base may also be provided with surgical instruments whichcan be used to stabilize or manipulate the heart during surgery.

Once access to the thoracic cavity has been achieved, surgery on theheart to effect valve replacement may be performed. During someprocedures, the heart beat is arrested by infusion of a cardioplegicfluid, such as potassium chloride (KCl), to paralyze the myocardiumwhile blood flow circulation is maintained through known heart bypasstechniques. Alternatively, the heart is allowed to beat to maintaincirculation, while a localized area of the heart, on which surgery is tobe performed is locally immobilized by various instruments.

The heart is incised and the defective valve is cut away leaving asurrounding area of locally tougher tissue. Known heart valvereplacement techniques typically include individually passing suturesthrough the tough tissue by hand to form an array of sutures. Free endsof the sutures are extended out of the thoracic cavity and laid, spacedapart, on the patient's body. The free ends of the sutures are thenindividually threaded through an edge around the circumference of thereplacement valve or a supporting cuff. This is also typicallyaccomplished by hand. Once all sutures have been run through the valve,all the sutures are pulled up taut and the valve is slid or “parachuted”down, by hand, into place adjacent the tough tissue. Thereafter, thereplacement valve is secured in place using the sutures. Since theconventional heart valve replacement techniques are exclusively manualprocedures, they are typically time consuming and difficult.

Where replacement is performed utilizing an artificial valve hand heldinstruments in the form of a stick may be affixed to the valve and usedto manipulate the replacement valve into place. The commerciallyavailable replacement valves are typically provided with a detachableholder structure which can be engaged by the hand tools.

While the above described procedures are sufficient to successfullyposition a heart valve within the heart, they are particularly timeconsuming. A more suitable apparatus would be desirable for maintainingthe valve in a position such that a plurality of sutures maysimultaneously pierce a cuff of the heart valve and thereafter assist inplacement of the heart valve in the heart to allow it to be secured inplace. Therefore, a need exists for apparatus and procedures of quicklyand efficiently positioning and affixing artificial heart valves withinthe heart.

SUMMARY OF THE DISCLOSURE

There are provided various embodiments of systems and methods forinstalling a synthetic, artificial heart valve within a patient. Thefirst system generally includes a plurality of sutures, each suturehaving a staple attached to a distal end thereof; a surgical stapler forradially discharging the staples into a heart at a location adjacent asite for installing the heart valve; a support assembly for releasablysupporting the plurality of sutures; and a heart valve setter assembly,the heart valve setter assembly being operable to move the heart valveinto position within the site in the heart.

Preferably the plurality of sutures also include a plurality of needlesattached to a proximal end thereof. The needles may then be securedwithin a plurality of grooves on an inner surface of the supportassembly with the pointed ends pointed proximally to facilitateinsertion through a cuff of a replacement heart valve, and into a ringshaped needle guard mounted on the support assembly. The supportassembly preferably includes a plurality of legs and a ring member,wherein the ring member is configured to interconnect the plurality oflegs at a proximal end thereof.

The heart valve setter assembly, which includes a heart valve holderassembly and a heart valve setting instrument, may be mounted on thesupport assembly to lower the heart valve replacement into apredetermined location within the heart. The heart valve holder assemblyincludes a shaft, a handle connected to a proximal end of the shaft, anda heart valve holder connected to a distal end of the shaft. The heartvalve setting instrument includes a shaft having a knurled proximalportion and a needle grasper connected to a distal end of the shaft, andis slidably mounted on the heart valve holder assembly. The heart valveis moved along the sutures into position within the predetermined sitein the heart.

A method of installing a heart valve within a patient is provided andgenerally includes the steps of accessing a site within a heart fromwhich a natural heart valve has been removed; positioning a surgicalstapler within the site; discharging a plurality of staples, havingsutures attached thereto, from the surgical stapler into the heart;lowering the heart valve along the sutures into position within the sitein the heart; and securing the heart valve to the heart with thesutures.

The method of installing a heart valve within a patient as describedabove, is preferably provided wherein the sutures have needles attachedto an end opposite the staples. The method further includes the step ofsecuring the sutures at a location above the site within the heart witha support assembly. Also prior to the step of lowering the heart valvealong the sutures the sutures are threaded through a cuff of the heartvalve to facilitate lowering the heart valve along the sutures intoposition within the site in the heart. Lastly, prior to the step ofsecuring the heart valve to the heart, the heart valve installationassembly is removed from the accessed site.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are described herein with reference to the drawings,wherein:

FIG. 1 is a perspective view of a patient with access to the thoraciccavity held open by a retractor;

FIG. 2 is an exploded perspective view of a support assembly for use inheart valve replacement surgery;

FIG. 3 is a partial cross-sectional side view of the support assembly ofFIG. 2 having a surgical stapler positioned therein:

FIG. 4 is an exploded perspective view of a heart valve setter assembly;

FIG. 5 is an exploded perspective view of the heart valve setterassembly of FIG. 4 being installed on the support assembly of FIG. 2;

FIG. 6 is a view of the heart valve setter assembly mounted on thesupport assembly above an opening in a thoracic cavity;

FIG. 7 is a view of the support assembly being separated to allow aheart valve to parachute down into a bore in a heart;

FIG. 8 is a view illustrating the removal of a heart valve holder fromthe heart valve; and

FIG. 9 is a perspective view of a plurality of sutures extending upwardfrom a heart valve positioned within a bore of a heart.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Various embodiments are disclosed herein which relate to installationsystems including tools and methods for quickly and efficientlypositioning and securing a synthetic replacement heart valve within theheart without the necessity of manually suturing the valve in place. Thedisclosed systems accomplish this objective by providing a supportassembly for supporting a plurality of sutures extending outward from aplurality of staples secured in a predetermined position within a sitein a heart, and a setter assembly for guiding a replacement heart valvedown along the suture lines into the predetermined position within theheart.

Referring now to the drawings in detail, and initially to FIG. 1, accessto the heart through the thoracic cavity is accomplished using wellknown surgical procedures. Generally an incision 50 is made through thesternum of a patient 52 to access the thoracic cavity 54 and expose theheart 56.

Preferably, access to the cavity is maintained with the assistance of aretractor 58, such as for example, the Mini-CABG* retractor and relatedaccessories available from United States Surgical Corporation, Norwalk.Conn. Retractor 58 generally includes an oval planar base 60 and ispositioned on patient 52 such that an opening 62 defined by base 60overlies incision 50. A plurality of retractor blades 64, 66, 68 . . .are slidably mounted on base 60 and engage and retract the tissue edgesof incision 50. Optionally, additional instruments may be affixed tobase 60 to manipulate and/or stabilize the heart 56 to facilitatesurgery thereon. Blood flow circulation may be maintained using knowntechniques. Thus, access to heart 56 is achieved and maintained. Otherknown open surgical procedures to access the heart are also contemplatedand may be substituted for the procedure described herein. Once accessto heart 56 has been obtained, heart 56 is opened and a dysfunctionalvalve is removed using known surgical procedures.

Referring now to FIG. 2, there is disclosed a support assembly 80 forsupporting and housing apparatus required for the replacement of a heartvalve. Support assembly 80 includes a two-piece support member 82 whichis preferably formed as a “quad-pod” which may be configured to bemounted on retractor base 60 shown in FIG. 1. Support member 82 includesa two-piece circular ring 84 and four legs 86. Ring 84 is attached toeach of the four legs 86 at proximal ends 87 thereof. Each half of ring84 contains a tab 88 extending therefrom on opposing sides thereof, thetabs 88 being configured and dimensioned to fit within an opening in theopposing ring half 84 to removably couple the two halves of ring 84. Asused herein the term “distal” refers to that portion of the assembly, orcomponent thereof, further from the user, while the term “proximal”refers to that part of the assembly, or component thereof, closer to theuser.

An inner surface 85 of ring 84 has a plurality of grooves or coaxialslots 90 formed therein for releasably securing a plurality of needles92. As will be discussed in further detail below, needles 92 arepreferably connected to proximal ends 93 of a plurality of sutures 94,and distal ends 95 of sutures 94 are connected to a correspondingplurality of staples 96.

A needle guard 98 is removably mounted on a proximal surface of ring 84and is positioned such that pointed ends of needles 92 pierce the lowersurface of needle guard 98. As best seen in FIGS. 2 and 3, needle guard98 preferably includes a plastic outer housing 100 having acircumferential groove therein, and a felt insert 102 positioned withinthe circumferential groove for releasably retaining the plurality ofneedles 92.

Referring now to FIG. 3, to install an artificial heart valve in heart56, support assembly 80 is positioned above an opening to a thoraciccavity of a patient and a surgical stapler 104 is positioned therein. Aproximal end 106 of stapler 104 includes an actuator handle 108 which isoperatively connected through shaft 110 to a staple retainer housing 112located on a distal end 114 of stapler 104.

A plurality of staples 96, which are preassembled with sutures 94 andneedles 92, are loaded into staple retainer housing 112 prior to beingdischarged into the intended surrounding tissue. Actuator handle 108 isconfigured such that a lever 116 is moved in the direction of arrow A tocause one or more staples to be simultaneously discharged from stapleretainer housing 112 in a radial direction as indicated by arrows Billustrated adjacent staple retainer housing 112. Preferably, stapler104 is configured to discharge a plurality of staples 96 in a singleshot i.e., a single actuation of lever 116. Alternatively, staple 104may be configured to hold and discharge a single staple 96 in responseto an actuation of lever 116. Thus, stapler 104 is a means for attachinga distal end of sutures to a heart.

As illustrated in FIG. 3, distal end 114 of stapler 104 is positionedwithin a bore 118 in heart 56 which was created by the removal of adysfunctional heart valve. Typically, following removal of adysfunctional heart valve, the surrounding area includes tougher tissuewhich is amenable to retaining staples and sutures. Once lever 116 isdepressed staples 96 are discharged into the circumference of bore 118formed in heart 56, and stapler 104 may be removed from support assembly80. Following removal of stapler 104, support assembly 80 may remainpositioned above the thoracic cavity of a patient and ready to receiveadditional tools. Sutures 94 extend proximally from staples 96, whichare secured to heart 56, and are attached to needles 92 which areremovably secured within ring 84 and needle guard 98.

Alternatively, it is contemplated that the distal ends of sutures 94 maybe manually attached to heart 56 (e.g., by threading), instead of usingstaples 96.

At this point, needle guard 98 may be removed to expose the pointed endsof needles 92. A heart valve may then be manually positioned adjacentneedles 92 such that needles 92 are caused to penetrate a cuff of theheart valve. The needles may then be pulled through the cuff with aconventional needle grasper to allow the heart valve to slide down thesutures into position within the heart. However, it is preferable to usea heart valve setter assembly in accordance with the present disclosureand discussed below.

Referring now to FIG. 4 there is disclose a heart valve setter assembly120 for use with support assembly 80 during heart valve replacementsurgery. Heart valve setter assembly 120 includes a heart valve holderassembly having a handle 122 connected to a proximal end of a shaft 124,a heart valve holder 126 connected to a distal end of shaft 124 and avalve setting instrument 128 having a longitudinal bore therein forslidably mounting on shaft 124. Valve setting instrument 128 includes ashaft 130 having a knurled proximal portion 132 and a needle grasper 134connected to a distal end. Similar to needle guard 98, needle grasper134 has a permeable felt insert 135 therein.

Also illustrated in FIG. 4 are heart valve assembly 136 suture retainerring 138 and needles 92 which are attached to sutures 94. Heart valveassembly 136 includes a valve cuff 142 and a valve ring 140 having aplurality of valve leaflets 144 pivotally mounted therein. Heart valvering 140 is generally formed by molding or machining a suitablebiocompatible material such as, for example, stainless steel. Valve cuff142 is preferably formed of a permeable felt, to facilitate penetrationthereof by needles 92.

Referring to FIG. 5, to proceed with the operation, needle guard 98(FIG. 3) has been removed to facilitate exposure of the pointed ends ofneedles 92 secured within ring 84. Heart valve assembly 136 and sutureretainer ring 138 are held by valve holder 126. The entire heart valvesetter assembly 120 is then moved distally in the direction of supportmember 82 such that needles 92 penetrate valve cuff 142 and sutureretainer ring 138, and heart valve setter assembly 120 is mounted onsupport member 82.

Turning now to FIG. 6, heart valve setter assembly 120 is shown mountedon support member 82, as described above, with needles 92 penetratingthrough valve cuff 142 and suture retainer ring 138. As illustrated,valve setting instrument 128 has been shifted distally along shaft 124such that needles 92 are secured within needle grasper 134.Specifically, needles 92 penetrate cuff 142 and engage permeable feltinsert 135 within needle grasper 134. Heart valve assembly 136 is nowready to be parachuted distally along sutures 94 and into its intendedposition within bore 118 of heart 56.

Turning now to FIG. 7, the two halves of support member 82 are separatedand moved outward from heart valve assembly 136 releasing needles 92from coaxial slots 90 to allow assembly 136 to be moved or parachuteddistally along sutures 94 into bore 118 of heart 56. To initiate andcontrol the distal movement of heart valve assembly 136, valve settinginstrument 128 is secured in a fixed position relative to handle 122,shaft 124 and heart valve holder 126. While knurled portion 132 is held,handle 122 may be depressed to force heart valve holder 126 to pushheart valve assembly 136 distally, thereby freeing it from being heldadjacent needle grasper 134 by needles 92 within valve cuff 142. Heartvalve assembly 136 may be guided distally along the sutures lines 94 byheart valve holder 126. The velocity of the distal movement of heartvalve assembly 136 may be controlled by the user via handle 122.

Once heart valve assembly 136 is properly positioned adjacent staples 96within bore 118 of heart 56, handle 122 is drawn proximally, asindicated by arrow C, to remove heart valve holder 126 from heart valveassembly 136, as shown in FIG. 8. Thereafter, valve setting instrument128 may be moved proximally to release needles 92 from permeable felt135 within needle grasper 134. Alternatively, sutures 94 may be cut atthe proximal end thereof, leaving pointed needles 92 engaged withpermeable felt 135 within needle grasper 134.

As illustrated in FIG. 9, valve setting instrument 128 has been removedleaving heart valve assembly 136 and suture retainer ring 138 positionedwithin bore 118 of heart 56 with sutures 94 and needles 92 extendingtherethrough. To complete the installation of heart valve assembly 136,adjacent pairs of sutures 136 may be tied and cut adjacent sutureretainer ring 138, or secured adjacent suture retainer ring 138 by anyother suitable means known to one having ordinary skill in the art.

It will be understood that various modifications may be made to theembodiments disclosed herein. For example it is noted that variouslydimensioned heart valve assemblies may be provided to facilitatereplacement of corresponding heart valves. Therefore, the abovedescription should not be construed as limiting but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

What is claimed is:
 1. A method of installing a heart valve within apatient comprising the steps of: accessing a site within a heart fromwhich a natural heart valve has been removed; positioning a surgicalstapler within the accessed site; discharging a plurality of staples,having sutures attached thereto, from the surgical stapler into theheart; lowering the heart valve along the sutures into position withinthe site in the heart; and securing the heart valve to the heart withthe sutures.
 2. The method as recited in claim 1, wherein the sutureshave needles attached to an end opposite the staples.
 3. The method asrecited in claim 1, further comprising the step of securing the suturesat a location above the accessed site with a support assembly prior tothe step of lowering the heart valve.
 4. The method as recited in claim3, further comprising the step of removing the support assembly from theaccessed site prior to the step of securing the heart valve to theheart.
 5. The method as recited in claim 1, further comprising the stepof inserting the sutures through a cuff of the heart valve prior to thestep of lowering the heart valve along the sutures.